But they probably have one thing in common — concern over their Toyota engines heading into the upcoming weeks.

The problems at Phoenix came on the heels of Busch and teammate Matt Kenseth both suffering engine failures in the Daytona 500.

A valve spring issue resulted in Hamlin’s engine needing to be replaced Saturday. Busch’s team misassembled his engine after replacing his valve springs prior to the race Sunday. When the team fired the engine in the garage, the motor broke.

When he found out about Busch’s engine,

Hamlin tweeted “Sigh…Unreal.” Hamlin said he couldn’t let the valve spring issue on his engine impact the way he raced.

“The drivers will not change any way that they drive to try to help reliability because if we do that, then we're altering our chances to win, and we're not going to do that,” Hamlin said.

The engines are built and maintained by Toyota Racing Development, so the Joe Gibbs Racing crews don’t have much responsibility as far as TRD quality control issues.

“There’s nothing else we can do,” Hamlin crew chief Darian Grubb said. “The TRD guys are doing a really good job working through the bugs that they have.

“We’re just going to keep going.”

Toyota teams did not have any engine issues during the actual race, compared to a week ago when it had three valve spring issues (one for JGR, one for Michael Waltrip Racing and one for Swan Racing) and a different issue with Kenseth’s engine in the Daytona 500.

“It always happens, you just hope it doesn’t happen to you,” Grubb said. “When it does, you’ve got to make sure you keep perspective on everything else. … We’ll keep working with those guys to make sure we dissect what’s going on and do our best to prevent it.”

The Daytona and Phoenix engine packages are different, so TRD Senior Vice President David Wilson said he doesn’t see the problems on back-to-back weekends as a systematic issue.

Wilson also said that the engines are specifically built for Toyota teams, so it’s not as if JGR is getting different equipment than MWR.

Wilson said the valve spring is the most delicate piece in the engine. The team buys its valve springs from a vendor, which Wilson wouldn’t name.

TRD is exploring all options as far as valve springs, Wilson said. But with just one valve spring issue at a non-restrictor-plate track, Wilson isn’t sure that the valve springs need to be changed.

“Every single engine builder in the garage will tell you their Achilles heel is and always will be the valve spring,” Wilson said. “That is the weakest link.”

When Toyota entered NASCAR’s Sprint Cup Series, TRD began building engines for MWR and the now-defunct Team Red Bull. Prior to the 2012 season, JGR opted to go with TRD after having problems and felt TRD’s experience with fuel injection would give it an edge.

“Our culture, our philosophy is to be involved in where we race,” Wilson said. “We want to learn something through that. We’re an engineering company, not a check-writing company.”

Last year, Busch had engine trouble in three consecutive races, which hindered his chances of making the Chase for the Sprint Cup (he missed the Chase).

“In being most critical of ourselves, our perspective is even though Kyle went to Richmond with a chance to make the Chase, … he wouldn’t have been in that position had he not had those engine failures,” Wilson said.

“Our perspective is we cost him a chance at competing for the championship.”